The broad concept of hydraulically actuated machines for making holes in putting greens is disclosed in U.S. Pat. No. 3,817,337 to Panak et al., wherein a wheeled vehicle, such as a greens mower, is provided with a hydraulically actuated cutting cylinder which is forced downwardly into the soil below the turf and then moved upwardly to form a hole in the ground, the soil plug then being ejected from the cutting cylinder.
While the known machines have been satisfactory for their intended purpose, they are characterized by certain disadvantages, most notably, in not being able to orient the cutter assembly in a vertical plane on the green regardless of its slope for digging a straight hole. Furthermore, the construction and arrangement of the ejection mechanism for removing the cut plug from the cutting cylinder did not facilitate the direct ejection of the plug from the cutting cylinder into the previously formed hole where the cup has been removed.
After considerable research and experimentation, the machine for making holes in putting greens has been devised which comprises, essentially, a frame connected to a wheeled vehicle, such as a greens mower. A carriage is slidably mounted on the frame, and a cutter assembly, including a cutting cylinder, is mounted on the carriage whereby the cutting assembly is movable in a vertical plane relative to the ground. The cutter assembly is freely pivoted to the carriage about orthogonal axes, whereby the cutter assembly can freely seek a vertical orientation regardless of the green slope. A releasable lock mechanism is operatively connected to the orthogonal axes to hold the cutter assembly in the vertical orientation, whereby a straight hole can be dug. A motor is mounted on the carriage for rotating the cutter assembly, and the cutter assembly is detachably connected to the motor drive shaft so that the cutting cylinder and associated soil plug can be manually moved to a previously formed hole and the plug ejected from the cutting cylinder into the hole. A depth gauge is provided between the frame and carriage indicating the depth of the cutter in the ground, and the carriage, lock mechanism and motor for rotating the cutter assembly are hydraulically driven through a hydraulic circuit connected to the mower.